- 2 scallions, white parts finely chopped and greens reserved for another use
- 1 tablespoon unsalted butter
- 1 to 2 finely chopped fresh jalapeño including seeds
- 1/2 cup heavy cream
- 1/2 teaspoon salt
- 4 (6- to 8-oz) pieces flounder fillet
- 1/8 teaspoon black pepper
- 1/2 cup quartered grape tomatoes
- 1 tablespoon chopped fresh cilantro
- Cook chopped scallions in butter in a 10-inch heavy skillet over moderate heat, stirring, until softened, 3 to 4 minutes. Add jalapeño (to taste), cream, and 1/4 teaspoon salt and bring to a simmer.
- Pat fish dry, then sprinkle with pepper and remaining 1/4 teaspoon salt. Fold each fillet in half crosswise. Put folded fish in sauce in skillet and cook at a bare simmer, covered, until fish is just cooked through, 5 to 6 minutes. Transfer fish to a platter and keep warm, covered with foil.
- Add tomatoes and cilantro to sauce in skillet, along with any fish juices on platter, and cook over moderately low heat until heated through, about 1 minute. Spoon sauce over fish.